" A woman will rarely do anything during a pickup that makes her feel responsible for what may happen between the two of you. To whatever degree she feels responsible, her anti-slut defense will be activated.
Thus she has a need for plausible deniability. For example, if you were to say to her, "Hey, let's go back to my place and have sex," she would have to say no, even though she wanted to say yes, because saying yes would make her responsible for what is happen——which she was never be.
But if instead you were to say, "Hey, let's stop by my place on the way to that party; I have to show you my tropical fish," now she has an excuse and plausbile deniability to stop by your place and then—oopsie!—have sex with you. "One thing led to another... "

― , The Mystery Method: How to Get Beautiful Women Into Bed